Anthropic Open-Sources FlashProve for Verifiable AI Model Inference
Anthropic has open-sourced FlashProve, a cryptographic tool that allows servers to mathematically prove which AI model generated a response, preventing reseller fraud. It enables fast verification on standard CPUs and offers significant efficiency gains over prior systems, with security guarantees formally verified in Lean 4.
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Rohan Paul (@rohanpaul_ai) · 2026-11-03 20
Anthropic just open-sourced FlashProve, which lets you check which AI model actually wrote a reply
checkable on an ordinary CPU.
e.g. if you pay for a top AI model through a reseller, you can’t check whether it quietly served a cheaper one. Anthropic’s FlashProve lets the server prove mathematically which model answered.
Anthropic tested it on Meta’s Llama 4 Maverick, a large 400B-parameter open model, where a single Nvidia H100 GPU produced proofs at 110 tokens/second, each about 19MB.
A regular CPU checks each proof in about 17 seconds, while VerInf, the only earlier system known to prove this model, made 93.6GB proofs that took almost a day to check.
Claude built the system, and because its code is hard to audit, the security guarantees are mathematically proved in Lean 4, a proof-checking language,
↳ 引用 @AnthropicAI (Anthropic): New Anthropic research: progress on provable inference for large language models.
Here, we introduce FlashProve. Building on established cryptographic techniques, FlashProve allows developers to verify whether a given response came from a given AI model. It’s substantially more efficient than prior open-source methods for doing so.
These proofs have a range of applications. They can, for instance, make it harder for attackers to hijack a chat, or enable safety evaluators to verify that the model they’re testing is the same one being served to customers.
For our full write-up, see here:
